La Sirena Koji

A Castillo from Colombia, grown on Juan David Puerta’s La Sirena farm in Quindío, Armenia, and processed using the natural method. The coffee was fermented with koji. This gives the coffee an umami-rich, full-bodied, tangy-sweet flavour profile.

The method of fermenting coffee with koji was developed by the bioscientist Koichi Higuchi. It involves the use of koji spores, a traditional mould (Aspergillus oryzae) used in the production of classic Japanese fermented foods such as soy sauce, miso, sake and mirin. In coffee fermentation, green coffee beans or harvested coffee cherries are mixed with koji cultures and fermented for several days under controlled conditions (25–30 °C, 70–90 per cent humidity). During this process, the enzymes produced by koji, such as amylases, proteases and lipases, break down complex carbohydrates, proteins and lipids, resulting in unique flavour profiles. The subsequent drying of the whole cherries further enhances the effect of the koji fermentation and ensures a distinctive aroma and flavour experience.